1. Field of the Invention
The present invention relates generally to an optical chip holder in a pigtailing system, and particularly to an automated optical chip holder that loads the optical chip and unloads the pigtailed optical chip in an automated mass-pigtailing system.
2. Technical Background
Optical fibers must be precisely and securely aligned with integrated optical chip waveguides during a pigtailing procedure. Otherwise, light signals propagating through the resulting device will be severely degraded by attenuation and other optical losses. In addition, processes depending on the extensive use of manpower, are undesirable. From an efficiency standpoint, it is most desirable that the entire pigtailing process for loading the optical chip, precision aligning, pigtailing, and unloading be automated and reproducible.
One approach that has been considered involves the use of vacuum chucks. Typically, the optical chip is placed on a chuck platform surface having air ducts which communicate to a plenum. Subsequently, the air in the plenum is evacuated and the resulting vacuum force holds the optical chip against the platform surface. However, this approach has several drawbacks. First, vacuum chucks tend to produce air fluctuations that induce small vibrations, perturbing the optical chip. Thus, the stability of the optical chip is not maintained during the curing of the glue. More importantly, retraction stresses during the curing of the glue cause the optical chip's waveguides to be misaligned with the fiber or fiber array block. As a result, the device has a lower reliability and the resulting optical losses are high. Another drawback associated with this method is the dependency on skilled labor. An operator is required to load the optical chip and unload the pigtailed optical chip manually. Since this is a very delicate operation, the success of the pigtailing process is largely dependent on the experience of the operator.
In another approach that has been considered, a slide mechanism is used to hold the optical chip in place. The face of the optical chip substrate is used as a support reference. The slide mechanism slides against the substrate face to clamp it against a support. Although the stability of the optical device is improved, the resulting chip thickness dispersion tends to negatively affect the reproducibility of the process. Like the method described above, this method requires that an operator load the optical chip and unload the pigtailed optical chip manually. Again, since this is a very delicate operation and the success of the pigtailing process is dependent on the experience of the operator.
Thus, a need exists for an automated chip holder that precisely, securely, and repeatedly positions and aligns optical chips within the pigtailing system. Further, a need exists for an automated chip holder that automatically loads the optical chip and unload the pigtailed optical chip with minimal operator involvement; one that is suitable for mass-producing pigtailed optical devices.